And even if you don't do any bussiness with them.
Oracle can sue anyone, they sue a lot.
Like most companies they only do so if they think they can make a profit.
They could sue you, with a higher chance of winning, for using a python, a js or a ruby than for using OpenJDK derived code.
They could sue you, with a higher chance of winning, for using a python, a js or a ruby than for using OpenJDK derived code.